Hazard analysis and critical control point dynamic management method for multi-product inline production

Abstract

The present application relates to the technical field of feed additive co-line production, and particularly discloses a hazard analysis and critical control point dynamic management method for multi-product co-line production, which comprises the following steps: setting multiple synchronous switching steam monitoring periods, performing time dimension lag analysis on steam switching, judging whether the steam control is lagged, avoiding the influence of residual high-temperature steam in the pipeline on subsequent low-temperature feed additives, and avoiding misjudgment of the entire system being emptied due to fast discharge of a pipeline, considering that the slowest pipeline is used as a reference, and ensuring that all pipelines are emptied before switching is completed, thereby fundamentally blocking the risk loopholes caused by the bucket effect, performing change analysis on the control lag degree of each switching lag production line, obtaining a lag adjustment time length, determining a single-line lag adjustment time period, and avoiding excessive adjustment, but instead, adaptive switching is performed according to actual fluctuation conditions, so that neither insufficient adjustment nor excessive adjustment occurs when the fluctuation is large or small.

Description

Technical Field

[0001] This invention relates to the field of feed additive co-production technology, specifically to a method for hazard analysis and dynamic management of critical control points in multi-product co-production. Background Technology

[0002] Co-production of feed additives refers to a continuous production model in which multiple feed additive products with different formulations and conditioning processes share the same set of production equipment and pipelines. Taking the switch from high-temperature conditioning products (such as poultry feed) to low-temperature conditioning products (such as young animal feed) as an example, poultry feed is usually conditioned at a higher temperature, requiring a large amount of high-temperature steam to fully cook the material. However, young animal feed is a low-temperature conditioning product, which has a clear upper limit requirement for steam temperature. Exceeding this upper limit will cause the material temperature to exceed the standard, and the heat-sensitive nutrients in the young animal feed (such as vitamins, enzymes, probiotics, etc.) will be inactivated, directly affecting the product quality.

[0003] In existing technologies, to prevent high-temperature steam from affecting subsequent low-temperature products, the common practice is to issue a steam valve closing command in advance during product switching to allow the high-temperature steam in the pipeline to be vented as quickly as possible. However, some problems exist in actual production. For example, there is a physical lag in the closing of the steam valve, and high-temperature steam inevitably remains in the pipeline. From the issuance of the valve closing command to the actual drop in steam temperature below the safety line, it often takes 3 to 5 minutes or even longer. During this period, the residual high-temperature steam continues to heat the material, causing the material temperature to exceed the standard and the heat-sensitive components to deactivate.

[0004] Co-line production involves multiple steam pipelines, each with different lengths, diameters, insulation conditions, and steam venting rates. Existing technologies often use the venting time of a single pipeline as the venting time of the entire system, or simply take an average value. This leads to pipelines with fast venting being mistakenly judged as having a safe system overall, while pipelines with slow venting still retain high-temperature steam, creating a bottleneck effect. Low-temperature products still face the risk of exceeding temperature limits during the initial switchover phase.

[0005] After adopting the pre-closing valve adjustment control, the steam load fluctuates greatly during the pre-adjustment control period. If the steam-water separator is not drained in time, saturated steam can easily carry water into the conditioner, causing a sudden increase in the moisture content of the feed additives in some areas. This sudden increase in moisture content can easily cause pelleting mold blockage and lead to excessive moisture in the finished product, resulting in mold growth later. Simultaneously, water carried by the steam dilutes the steam heat, causing unstable conditioning temperature, fluctuating material maturity, and poor product quality consistency. Even if the steam flow rate and feed rate are both within normal ranges, if they are not synchronized in time—for example, the steam flow rate reaches its peak before the feed rate, creating a "less feed, more steam" gap—the saturated steam carrying water will rush in before the material has arrived, causing a sudden increase in local moisture content and a still high risk of mold blockage. Current technology lacks quantitative analysis methods for the synchronicity of steam flow rate and feed rate in the time dimension.

[0006] Therefore, this invention provides a method for hazard analysis and dynamic management of critical control points in multi-product co-production. Summary of the Invention

[0007] The purpose of this invention is to provide a method for hazard analysis and dynamic management of critical control points in multi-product co-production, so as to solve the aforementioned background problems.

[0008] The objective of this invention can be achieved through the following technical solutions:

[0009] Hazard analysis and dynamic management methods for critical control points in multi-product co-production lines include:

[0010] During the switching of feed additive products in the co-production of feed additives, multiple synchronous switching steam monitoring cycles are set, and the time dimension lag analysis of steam switching is performed to determine whether the steam control is lagging. If the steam control is lagging, it is marked as a lagging production line.

[0011] Analyze the changes in the control lag degree of each switching lag production line to obtain the lag adjustment duration and determine the single-line lag adjustment period.

[0012] The steam flow rate and feed additive dosage were obtained during each single-line lag adjustment period. Steam-feed difference analysis was performed, and the risk of pelleting blockage was assessed by combining the differences in steam flow rate and feed additive dosage over time.

[0013] When assessing high-risk pelleting blockage, the dynamic feed compensation amount is obtained, and the feed additive feed is dynamically managed in real time by combining changes in steam flow.

[0014] As a further aspect of the present invention, the process of performing a time-dimensional lag analysis on steam switching is as follows:

[0015] During the switching of steam monitoring cycles, the time point when the steam valve closing command is issued is extracted as the command issuance time point;

[0016] During the switching of steam monitoring cycles, the steam temperature in each steam pipeline is acquired in real time, and a steam temperature change curve is constructed.

[0017] Mark the preset switching feed additive steam temperature on the Y-axis of the steam temperature change curve, and draw a straight line parallel to the X-axis as the high-temperature steam venting line.

[0018] Extract the coordinates of the points on the steam temperature change curve that intersect with or are below the high-temperature steam venting line, and select the point corresponding to the smallest X-axis coordinate as the single-path high-temperature steam venting time point.

[0019] As a further aspect of the present invention, the marking process for switching the lagging production line is as follows:

[0020] Compare the time points of single-line high-temperature steam venting for all steam pipelines and select the time point with the largest single-line high-temperature steam venting time as the high-temperature steam venting time point;

[0021] The time between the issuance of the instruction and the release of high-temperature steam is used as the control hysteresis identification value.

[0022] If the control lag identification value is greater than the control lag identification threshold, it will be displayed as a control lag signal and marked as a switchover lag production line.

[0023] As a further aspect of the present invention, the process for obtaining the hysteresis adjustment duration is as follows:

[0024] The control lag identification value corresponding to the switching lag production line is subtracted from the control lag identification threshold, and the ratio of the difference to the control lag identification threshold is calculated to obtain the periodic lag degree value.

[0025] The standard deviation of the lag value for each period is calculated to obtain the change in lag value;

[0026] If the change in lag degree is greater than the lag degree change threshold, a lag dynamic control strategy is implemented. The maximum periodic lag degree value is extracted as the lag adjustment amount, and multiplied with the control lag identification threshold to obtain the lag adjustment duration.

[0027] If the change in lag degree is less than or equal to the lag degree change threshold, a lag static control strategy is implemented. The average of all periodic lag degree values ​​is summed and multiplied with the control lag identification threshold to obtain the lag adjustment time.

[0028] As a further aspect of the present invention, the process for determining the single-line lag adjustment period is as follows:

[0029] Extract the timing of the instruction to switch to the lagging production line, combine it with the lag adjustment duration to perform time advance operation, and determine the timing of the instruction to be issued for adjustment;

[0030] The time interval between the time point when the instruction to adjust is issued and the time point when the high-temperature steam is vented from each single-line production line with a switching lag is defined as the single-line lag adjustment period.

[0031] As a further aspect of the present invention, the process of gas-fuel difference analysis is as follows:

[0032] Each single-line lag adjustment period is equally divided into several single-line adjustment monitoring points. The real-time steam flow rate and real-time feed additive feeding amount at each single-line adjustment monitoring point are obtained, the ratio is calculated, the instantaneous steam-feed ratio is determined, and the difference is calculated with the standard conditioning steam-feed ratio to obtain the steam-feed ratio deviation value.

[0033] The coefficient of variation of all gas-fuel ratio deviations within the single-line lag adjustment period is calculated to obtain the gas-fuel matching value for that period.

[0034] As a further aspect of the present invention, the analysis process of the difference between the changes in steam flow rate and feed additive dosage over time is as follows:

[0035] Real-time steam flow rate change curve and real-time feed additive amount change curve are constructed by adjusting the real-time steam flow rate and real-time feed additive amount at each single line monitoring point.

[0036] Extract the peak and trough coordinates of the real-time steam flow rate change curve as peak and trough flow rate coordinates, and construct peak and trough coordinate sequences.

[0037] Extract the peak and trough coordinates of the real-time feed rate change curve as the peak and trough coordinates of the feed rate, and construct the feed rate peak coordinate sequence and feed rate trough coordinate sequence.

[0038] As a further aspect of the present invention, the assessment process for the risk of pelleting blockage is as follows:

[0039] The first peak steam flow rate coordinate and the first peak feed amount coordinate of the peak steam coordinate sequence and the peak feed coordinate sequence are obtained. The time interval is calculated and the ratio is calculated with the synchronous switching steam monitoring cycle duration to obtain the unit peak duration deviation value. The average value is then calculated to obtain the peak deviation duration difference value.

[0040] The first steam valley flow rate coordinate and the first feeding valley quantity coordinate of the steam valley coordinate sequence and the feeding valley coordinate sequence are obtained. The time interval is calculated and the ratio is calculated with the synchronous switching steam monitoring cycle duration to obtain the unit valley duration deviation value. The average value is then calculated to obtain the valley deviation duration difference value.

[0041] The difference in peak offset duration and the difference in valley offset duration are summed to obtain the synchronization response difference.

[0042] The summation of the time-period gas-material matching value and the synchronous response difference yields the blockage risk analysis value.

[0043] As a further aspect of the present invention, the process for obtaining the dynamic feeding compensation amount when assessing high-risk pelleting die blockage is as follows:

[0044] If the blockage risk analysis value is greater than the blockage risk analysis threshold, it will be displayed as a high blockage signal;

[0045] The real-time steam flow rate of each single-line adjustment monitoring point is obtained and the ratio is calculated with the standard conditioning steam-to-material ratio to obtain the unit feed matching amount;

[0046] The difference between the unit feeding matching amount and the corresponding real-time feed additive feeding amount is calculated, and the positive and negative difference values ​​are retained without absolute value processing to obtain the initial dynamic feeding adjustment value.

[0047] The excess risk coefficient is obtained by subtracting the blockage risk analysis value from the blockage risk analysis threshold.

[0048] The dynamic feeding compensation amount is obtained by multiplying the risk excess coefficient with the initial dynamic feeding adjustment value.

[0049] As a further aspect of the present invention, the real-time dynamic management process is as follows:

[0050] Extract the dynamic feeding compensation amount and the corresponding synchronous response difference, substitute them into the formula, and obtain the corrected dynamic feeding compensation amount.

[0051] The corrected dynamic feed compensation amount is summed with the real-time feed additive amount to obtain the dynamic adjustment management value.

[0052] The beneficial effects of this invention are as follows:

[0053] 1. In the process of switching feed additive products in the co-production of feed additives, this invention sets multiple synchronous switching steam monitoring cycles, performs time-dimensional lag analysis on steam switching, determines whether steam control is lagging, avoids the impact of residual high-temperature steam in the pipeline on subsequent low-temperature feed additives, and also avoids the misjudgment that the entire system is empty because a certain pipeline is emptying quickly. Considering that the slowest pipeline is taken as the standard, the switching is considered complete only when all pipelines are empty, fundamentally plugging the risk loopholes caused by the barrel effect. The change analysis of the control lag degree of each lagging production line is carried out to obtain the lag adjustment time and determine the single-line lag adjustment period, avoiding over-adjustment, and instead adaptively switching according to the actual fluctuation situation, so that there is no under-adjustment when the fluctuation is large, nor over-adjustment when the fluctuation is small.

[0054] 2. This invention acquires the steam flow rate and feed additive dosage during each single-line lag adjustment period and performs difference analysis to assess the risk of pelleting clogging. This avoids the one-sided judgment that normal steam flow rate or normal dosage will prevent clogging, thus improving the accuracy of identifying pelleting clogging risk. When a high-risk pelleting clogging is assessed, a dynamic dosage compensation is acquired and combined with changes in steam flow rate to perform real-time dynamic management of feed additive dosage. The synchronous response difference is used to quantify the length of this gap period, and then additional dosage is added proportionally to eliminate the risk of the gap period. This addresses the root cause of clogging caused by water, rather than waiting for clogging to occur before taking action, thus achieving dynamic reduction of pelleting clogging risk. Attached Figure Description

[0055] The invention will now be further described with reference to the accompanying drawings.

[0056] Figure 1 This is a flowchart illustrating the steps of the hazard analysis and dynamic management of critical control points for multi-product co-production according to the present invention.

[0057] Figure 2 This is a flowchart illustrating the hazard analysis and dynamic management of critical control points for multi-product co-production in this invention. Detailed Implementation

[0058] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0059] Example 1

[0060] In the co-production process of feed additives, when switching from high-temperature conditioned products (poultry feed) to low-temperature conditioned products (livestock feed), delayed closure of steam valves or residual steam in the pipeline can cause the material temperature to exceed the standard for the first 3-5 minutes, leading to the deactivation of heat-sensitive components. Furthermore, even after adjusting the steam valves to allow for delayed closure, if the steam load fluctuates significantly during the adjustment period and the steam-water separator fails to drain in time, saturated steam can carry over water, causing a sudden increase in the moisture content of the feed additives. This not only easily leads to pelleting blockage but also results in excessive moisture content in the finished product, causing later mold growth. Simultaneously, the water carries over dilutes the steam heat, resulting in unstable conditioning temperatures and fluctuating degrees of ripening. Therefore, if… Figure 1 - Figure 2 As shown, this embodiment provides a method for hazard analysis and dynamic management of critical control points in multi-product co-production, including:

[0061] Step 1: During the product switching process of feed additives in the co-production of feed additives, set multiple synchronous switching steam monitoring cycles, perform time-dimensional lag analysis on steam switching, and determine whether steam control is lagging. If steam control is lagging, mark it as a production line with switching lag.

[0062] Among them, the synchronous switching steam monitoring cycle refers to the period during which the valves on multiple feed additive production lines are synchronously monitored for steam switching lag analysis within the same switching steam monitoring cycle;

[0063] In some embodiments, during the switching of steam monitoring cycles, the time point at which the steam valve closing command is issued is extracted as the command issuance time point;

[0064] The timing of the instruction issued for each switching steam monitoring cycle is the same;

[0065] During the switching of steam monitoring cycles, the steam temperature in each steam pipeline is acquired in real time, and a steam temperature change curve is constructed with the X-axis representing time and the Y-axis representing steam temperature according to the order of acquisition time.

[0066] It should be noted that each steam pipeline corresponds to a steam temperature change curve;

[0067] Mark the preset switching feed additive steam temperature on the Y-axis of the steam temperature change curve, and draw a straight line parallel to the X-axis as the high-temperature steam venting line.

[0068] It should be noted that the preset steam temperature for switching feed additives refers to the upper limit of the steam temperature that the feed can withstand when switching from a high-temperature product (poultry feed) to a low-temperature product (livestock feed). Exceeding this temperature will cause the material temperature to exceed the limit and the heat-sensitive components to become inactive. Therefore, it refers to the upper limit of the steam temperature that the next low-temperature product can tolerate.

[0069] Extract the coordinate points on the steam temperature change curve that intersect with or are below the high-temperature steam venting line, and compare the magnitudes of the X-axis coordinates corresponding to each coordinate point. Select the smallest X-axis coordinate as the single-path high-temperature steam venting time point.

[0070] Compare the time points of single-line high-temperature steam venting for all steam pipelines and select the time point with the largest single-line high-temperature steam venting time as the high-temperature steam venting time point;

[0071] The time between the issuance of the instruction and the release of high-temperature steam is used as the control hysteresis identification value.

[0072] It is understandable that the control lag identification value represents the time elapsed between the time the control system issues the command to close the steam control valve and the time elapsed between the time when the last steam pipeline in all pipelines has completely cooled below the safety line. Specifically, a larger control lag identification value indicates a longer time elapsed between the time the control system issues the command to close the steam control valve and the time when the last steam pipeline in all pipelines has completely cooled below the safety line, meaning lower steam control accuracy and indicating control lag. Conversely, a larger control lag identification value indicates a shorter time elapsed between the time the control system issues the command to close the steam control valve and the time when the last steam pipeline in all pipelines has completely cooled below the safety line, meaning higher steam control accuracy and indicating no control lag.

[0073] If the control lag identification value is greater than the control lag identification threshold, it means that the time between the time when the control system issues the instruction to close the steam control valve and the time when the last of all steam pipelines has completely cooled down below the safety line is relatively long. This is displayed as a control lag signal and marked as a switching lag production line.

[0074] If the control lag identification value is less than or equal to the control lag identification threshold, it means that the time between the time when the control system issues the instruction to close the steam control valve and the time when the last of all steam pipelines has completely cooled down below the safety line is short. This is displayed as a control non-lag signal and marked as switching to a non-lag production line.

[0075] Step 2: Analyze the changes in the control lag degree of each switching lag production line, obtain the lag adjustment duration, and determine the single-line lag adjustment period;

[0076] In some embodiments, the control lag identification value corresponding to the switching lag production line is subtracted from the control lag identification threshold, and the ratio of the difference to the control lag identification threshold is calculated to obtain the periodic lag degree value.

[0077] The standard deviation of the lag value for each period is calculated to obtain the change in lag value;

[0078] If the change value of the lag degree is greater than the lag degree change threshold, it indicates that the lag fluctuation of the switching steam control on different switching lag production lines is large. In this case, a lag dynamic control strategy is implemented, the maximum periodic lag degree value is extracted as the lag adjustment amount, and it is multiplied with the control lag identification threshold to obtain the lag adjustment time.

[0079] If the change value of the lag degree is less than or equal to the lag degree change threshold, it indicates that the lag fluctuation of the switching steam control on different switching lag production lines is small. Then, a lag static control strategy is implemented, and the average value of all periodic lag degree values ​​is calculated and multiplied with the control lag identification threshold to obtain the lag adjustment time.

[0080] Extract the timing of the instruction to switch to the lagging production line, combine it with the lag adjustment duration to perform time advance operation, and determine the timing of the instruction to be issued for adjustment;

[0081] The time interval between the time point when the instruction to adjust is issued and the time point when the high-temperature steam is vented from each single-line production line with a switching lag is defined as the single-line lag adjustment period.

[0082] The specific solution in this embodiment is as follows: During the switching process of feed additive products in the co-production of feed additives, multiple synchronous switching steam monitoring cycles are set. A time-dimensional lag analysis is performed on the steam switching to determine whether the steam control is lagging. This avoids residual high-temperature steam in the pipeline from affecting subsequent low-temperature feed additives. Furthermore, it avoids misjudging the entire system as empty simply because one pipeline is emptying faster. Considering the slowest pipeline as the benchmark, the switching is considered complete only when all pipelines are empty. This fundamentally plugs the risk loopholes caused by the "weakest link" effect. The control lag degree of each lagging production line is analyzed to obtain the lag adjustment time and determine the single-line lag adjustment period. Over-adjustment is avoided; instead, the switching is adaptively adjusted according to actual fluctuations, ensuring neither insufficient adjustment during large fluctuations nor excessive adjustment during small fluctuations.

[0083] Example 2

[0084] like Figure 1 - Figure 2 As shown, this embodiment provides a method for hazard analysis and dynamic management of critical control points in multi-product co-production, which specifically includes:

[0085] Step 3: Obtain the steam flow rate and feed additive dosage during each single-line lag adjustment period, perform steam-feed difference analysis, and assess the risk of pelleting blockage by combining the changes in steam flow rate and feed additive dosage over time.

[0086] In some embodiments, each single-line lag adjustment period is equally divided into several single-line adjustment monitoring points, wherein the interval between adjacent single-line adjustment monitoring points is equal.

[0087] The real-time steam flow rate and real-time feed additive feeding amount are obtained at each single-line adjustment monitoring point. The ratio is calculated to determine the instantaneous steam-feed ratio. The difference between the instantaneous steam-feed ratio and the standard conditioning steam-feed ratio (the benchmark value of low-temperature young animal feed) is calculated to obtain the steam-feed ratio deviation value.

[0088] The average value of the steam-material ratio deviation is calculated by summing all the deviation values ​​of steam-material ratio within the single-line lag adjustment period.

[0089] The standard deviation of the steam-material ratio deviation is obtained by calculating the standard deviation of all steam-material ratio deviations within the single-line lag adjustment period.

[0090] The standard deviation and mean deviation of steam and feed were calculated using the coefficient of variation formula to obtain the steam-feed matching value for the time period.

[0091] Real-time steam flow rate change curve and real-time feed additive amount change curve are constructed by adjusting the real-time steam flow rate and real-time feed additive amount at each single line monitoring point.

[0092] Among them, the real-time steam flow rate change curve is based on the X-axis as time and the Y-axis as real-time steam flow rate, and the real-time feed rate change curve is based on the X-axis as time and the Y-axis as real-time feed rate.

[0093] Extract the peak and trough coordinates of the real-time steam flow rate curve and use them as peak and trough flow rate coordinates.

[0094] Extract the peak and trough coordinates of the real-time feed rate change curve as the peak and trough coordinates of the feed rate.

[0095] For example, the peak steam flow coordinates and valley steam flow coordinates are sorted according to their time sequence on the real-time steam flow change curve to construct peak steam flow coordinate sequences and valley steam flow coordinate sequences.

[0096] The real-time feed rate change curves are sorted according to the time sequence on the real-time feed rate change curves to construct the feed peak coordinate sequence and the feed valley coordinate sequence.

[0097] The first peak steam flow rate coordinate and the first peak feed amount coordinate of the steam peak coordinate sequence and the feeding peak coordinate sequence are obtained. The time interval is calculated and the ratio is calculated with the synchronous switching steam monitoring cycle duration to obtain the unit peak duration deviation value.

[0098] The peak deviation duration difference is obtained by summing and averaging all the peak duration deviation values ​​of the units.

[0099] The first steam valley flow rate coordinate and the first feeding valley quantity coordinate of the steam valley coordinate sequence and the feeding valley coordinate sequence are obtained. The time interval is calculated and the ratio is calculated with the synchronous switching steam monitoring cycle duration to obtain the unit valley duration deviation value.

[0100] The valley duration deviation values ​​of all units are summed and averaged to obtain the valley deviation duration difference.

[0101] The difference in peak offset duration and the difference in valley offset duration are summed to obtain the synchronization response difference.

[0102] The summation of the time-period gas-material matching value and the synchronous response difference yields the blockage risk analysis value.

[0103] It is understandable that the meaning of the mold blockage risk analysis value is: reflecting the degree of risk of mold blockage in pelleting during the single-line lag adjustment period. On the one hand, the steam-material matching value of the time period reflects the degree of instability of the steam-material ratio in the quantitative dimension. On the other hand, the synchronous response difference reflects the degree of water carryover risk caused by time misalignment. Specifically, if the mold blockage risk analysis value is larger, it means that the fluctuation of the steam-material ratio and the time misalignment of steam flow and feed amount are both larger during the single-line lag adjustment period. If the mold blockage risk analysis value is smaller, it means that the fluctuation of the steam-material ratio and the time misalignment of steam flow and feed amount are both smaller during the single-line lag adjustment period.

[0104] If the mold blockage risk analysis value is greater than the mold blockage risk analysis threshold, it indicates that the fluctuation of the steam-material ratio and the time misalignment of steam flow and feed amount are both large during the single-line lag adjustment period, which is a high mold blockage signal.

[0105] If the mold blockage risk analysis value is less than or equal to the mold blockage risk analysis threshold, it indicates that the fluctuation of the steam-material ratio and the time misalignment of steam flow and feed amount are relatively small during the single-line lag adjustment period, which shows a low degree of mold blockage signal.

[0106] Step 4: When assessing high-risk pelleting blockage, obtain the dynamic feed compensation amount and simultaneously combine it with changes in steam flow rate to conduct real-time dynamic management of feed additive feeding.

[0107] In some embodiments, the real-time steam flow rate of each single-line adjustment monitoring point is obtained and the ratio with the standard conditioning steam-to-material ratio is calculated to obtain the unit feed matching amount;

[0108] The difference between the unit feeding matching amount and the corresponding real-time feed additive feeding amount is calculated, and the positive and negative difference values ​​are retained without absolute value processing to obtain the initial dynamic feeding adjustment value.

[0109] A positive initial dynamic feeding adjustment value indicates insufficient feeding and the need to increase feeding; a negative initial dynamic feeding adjustment value indicates excessive feeding and the need to reduce feeding.

[0110] The difference between the blockage risk analysis value and the blockage risk analysis threshold is used to obtain the risk excess coefficient;

[0111] The dynamic feeding compensation amount is obtained by multiplying the risk excess coefficient with the initial dynamic feeding adjustment value.

[0112] Extract the dynamic feeding compensation amount and the corresponding synchronous response difference, substitute them into the formula, and obtain the corrected dynamic feeding compensation amount.

[0113] The dynamic adjustment management value is obtained by summing the corrected dynamic feeding compensation amount with the real-time feed additive feeding amount.

[0114] The formula is: Corrected dynamic feeding compensation amount = Dynamic feeding compensation amount × (1 + Synchronous response difference).

[0115] It should be noted that the physical meaning of the revised dynamic feeding compensation amount is as follows: Since the fluctuation of the steam-material ratio and the time misalignment of steam flow and feeding amount are both relatively high during the single-line lag adjustment period, the dynamic feeding compensation amount can only solve the technical problem of the current steam-material ratio mismatch. The revised dynamic feeding compensation amount takes into account that the steam rises first and the feeding rises later, with a gap period of less material and more steam in between, which is prone to water blockage of the mold. Moreover, the larger the synchronous response difference, the more serious the misalignment. Therefore, more material is added to smooth out the risk of this gap period.

[0116] The specific solution in this embodiment is as follows: The steam flow rate and feed additive dosage during each single-line lag adjustment period are obtained, and the degree of difference is analyzed to assess the risk of pelleting clogging. This avoids the one-sided judgment that normal steam flow rate or normal dosage will prevent clogging, thus improving the accuracy of identifying pelleting clogging risk. When a high-risk pelleting clogging is assessed, a dynamic dosage compensation is obtained, and feed additive dosage is dynamically managed in real time in conjunction with changes in steam flow rate. The synchronous response difference is used to quantify the length of this gap period, and then additional dosage is added proportionally to eliminate the risk of the gap period. This addresses the root cause of clogging caused by water, rather than waiting for clogging to occur before taking action, thus achieving dynamic reduction of pelleting clogging risk.

[0117] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the present invention should still fall within the scope of the present invention.

Claims

1. A method for hazard analysis and dynamic management of critical control points in multi-product co-production lines, characterized by: include: During the switching of feed additive products in the co-production of feed additives, multiple synchronous switching steam monitoring cycles are set, and the time dimension lag analysis of steam switching is performed to determine whether the steam control is lagging. If the steam control is lagging, it is marked as a lagging production line. Analyze the changes in the control lag degree of each switching lag production line to obtain the lag adjustment duration and determine the single-line lag adjustment period. Obtain the steam flow rate and feed additive dosage during each single-line lag adjustment period, perform steam-feed difference analysis, and assess the risk of pelleting blockage by combining the differences in steam flow rate and feed additive dosage over time. When assessing high-risk pelleting blockage, the dynamic feed compensation amount is obtained, and the feed additive feed is dynamically managed in real time by combining changes in steam flow.

2. The method for hazard analysis and dynamic management of critical control points in multi-product co-production as described in claim 1, characterized in that: The process of performing a time-dimensional lag analysis on steam switching is as follows: During the switching of steam monitoring cycles, the time point when the steam valve closing command is issued is extracted as the command issuance time point; During the switching of steam monitoring cycles, the steam temperature in each steam pipeline is acquired in real time, and a steam temperature change curve is constructed. Mark the preset switching feed additive steam temperature on the Y-axis of the steam temperature change curve, and draw a straight line parallel to the X-axis as the high-temperature steam venting line. Extract the coordinates of the points on the steam temperature change curve that intersect with or are below the high-temperature steam venting line, and select the point corresponding to the smallest X-axis coordinate as the single-path high-temperature steam venting time point.

3. The method for hazard analysis and dynamic management of critical control points in multi-product co-production as described in claim 2, characterized in that: The marking process for switching to a lagging production line is as follows: Compare the time points of single-line high-temperature steam venting for all steam pipelines and select the time point with the largest single-line high-temperature steam venting time as the high-temperature steam venting time point; The time between the issuance of the instruction and the release of high-temperature steam is used as the control hysteresis identification value. If the control lag identification value is greater than the control lag identification threshold, it will be displayed as a control lag signal and marked as a switchover lag production line.

4. The method for hazard analysis and dynamic management of critical control points in multi-product co-production as described in claim 1, characterized in that: The process for obtaining the lag adjustment duration is as follows: The control lag identification value corresponding to the switching lag production line is subtracted from the control lag identification threshold, and the ratio of the difference to the control lag identification threshold is calculated to obtain the periodic lag degree value. The standard deviation of the lag value for each period is calculated to obtain the change in lag value; If the change in lag degree is greater than the lag degree change threshold, a lag dynamic control strategy is implemented. The maximum periodic lag degree value is extracted as the lag adjustment amount, and multiplied with the control lag identification threshold to obtain the lag adjustment duration. If the change in lag degree is less than or equal to the lag degree change threshold, a lag static control strategy is implemented. The average of all periodic lag degree values ​​is summed and multiplied with the control lag identification threshold to obtain the lag adjustment time.

5. The method for hazard analysis and dynamic management of critical control points in multi-product co-production as described in claim 4, characterized in that: The process for determining the single-line lag adjustment period is as follows: Extract the timing of the instruction to switch to the lagging production line, combine it with the lag adjustment duration to perform time advance operation, and determine the timing of the instruction to be issued for adjustment; The time interval between the time point when the instruction to adjust is issued and the time point when the high-temperature steam is vented from each single-line production line with a switching lag is defined as the single-line lag adjustment period.

6. The method for hazard analysis and dynamic management of critical control points in multi-product co-production as described in claim 1, characterized in that: The process of gas feed differential analysis is as follows: Each single-line lag adjustment period is equally divided into several single-line adjustment monitoring points. The real-time steam flow rate and real-time feed additive feeding amount at each single-line adjustment monitoring point are obtained, the ratio is calculated, the instantaneous steam-feed ratio is determined, and the difference is calculated with the standard conditioning steam-feed ratio to obtain the steam-feed ratio deviation value. The coefficient of variation of all gas-fuel ratio deviations within the single-line lag adjustment period is calculated to obtain the gas-fuel matching value for that period.

7. The method for hazard analysis and dynamic management of critical control points in multi-product co-production as described in claim 1, characterized in that: The analysis of the differences in steam flow rate and feed additive dosage over time is as follows: Real-time steam flow rate change curve and real-time feed additive amount change curve are constructed by adjusting the real-time steam flow rate and real-time feed additive amount at each single line monitoring point. Extract the peak and trough coordinates of the real-time steam flow rate change curve as peak and trough flow rate coordinates, and construct peak and trough coordinate sequences. Extract the peak and trough coordinates of the real-time feed rate change curve as the peak and trough coordinates of the feed rate, and construct the feed rate peak coordinate sequence and feed rate trough coordinate sequence.

8. The method for hazard analysis and dynamic management of critical control points in multi-product co-production as described in claim 7, characterized in that: The process for assessing the risk of pelleting clogging is as follows: The first peak steam flow rate coordinate and the first peak feed amount coordinate of the peak steam coordinate sequence and the peak feed coordinate sequence are obtained. The time interval is calculated and the ratio is calculated with the synchronous switching steam monitoring cycle duration to obtain the unit peak duration deviation value. The average value is then calculated to obtain the peak deviation duration difference value. The first steam valley flow rate coordinate and the first feed valley quantity coordinate of the steam valley coordinate sequence and the feed valley coordinate sequence are obtained. The time interval is calculated and the ratio is calculated with the synchronous switching steam monitoring cycle duration to obtain the unit valley duration deviation value. The average value is then calculated to obtain the valley deviation duration difference value. The difference in peak offset duration and the difference in valley offset duration are summed to obtain the synchronization response difference. The summation of the time-period gas-material matching value and the synchronous response difference yields the blockage risk analysis value.

9. The method for hazard analysis and dynamic management of critical control points in multi-product co-production as described in claim 8, characterized in that: When assessing high-risk pelleting die blockage, the process for obtaining dynamic feed compensation is as follows: If the blockage risk analysis value is greater than the blockage risk analysis threshold, it will be displayed as a high blockage signal; The real-time steam flow rate of each single-line adjustment monitoring point is obtained and the ratio is calculated with the standard conditioning steam-to-material ratio to obtain the unit feed matching amount; The difference between the unit feeding matching amount and the corresponding real-time feed additive feeding amount is calculated, and the positive and negative difference values ​​are retained without absolute value processing to obtain the initial dynamic feeding adjustment value. The excess risk coefficient is obtained by subtracting the blockage risk analysis value from the blockage risk analysis threshold. The dynamic feeding compensation amount is obtained by multiplying the risk excess coefficient with the initial dynamic feeding adjustment value.

10. The method for hazard analysis and dynamic management of critical control points in multi-product co-production according to claim 1, characterized in that: The real-time dynamic management process is as follows: Extract the dynamic feeding compensation amount and the corresponding synchronous response difference, substitute them into the formula, and obtain the corrected dynamic feeding compensation amount. The corrected dynamic feed compensation amount is summed with the real-time feed additive amount to obtain the dynamic adjustment management value.

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